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Message: <blockquote data-quote="Binastro" data-source="post: 3169629" data-attributes="member: 111403">. Regarding the last post 22.At 1504 UTC today, with a fairly clear sky, which was not transparent but rather milky, I had another go projecting the sun's image onto the wall and onto white card.By increasing the projection distance to about 40 cm and with the two images of the Sun about 4 cm across, I could just see the 2 sunspots, which are fairly close together. They are equally large with an approximate penumbral size of 25 arc seconds each.However, if I had not known that the sunspots were there it would have been difficult to notice them with a handheld 10×25 binocular. Had the binocular been mounted on a tripod I think that the two sunspots would have been seen fairly certainly.The image is still quite bright at a 40 cm projection distance with 4 cm images of the Sun.The sunspots are probably about 0.5mm across with a 40 cm projection distance and 4 centimetre images of the Sun. I was probably viewing them from about 50 cm.I am happy to use a good quality 10×25 binocular for short periods of projection, but I would not feel confident using a high quality 10×42 binocular for fear of the Sun's heat damaging the eyepieces, particularly any cemented pairs of elements.</blockquote>